ATP-dependent strontium uptake by basolateral membrane vesicles from rat renal cortex in the absence or presence of calcium
| Autor: | Naoko Sugihira, Kazuo T. Suzuki, Yasunobu Aoki |
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| Rok vydání: | 1992 |
| Předmět: |
inorganic chemicals
Male medicine.medical_specialty Kidney Cortex Endocrinology Diabetes and Metabolism Renal cortex Clinical Biochemistry chemistry.chemical_element Biological Transport Active Calcium Biochemistry Basement Membrane Inorganic Chemistry Adenosine Triphosphate Internal medicine medicine Animals Vanadate Rats Wistar Ouabain Epithelial polarity Kidney Chemistry Reabsorption Vesicle Biochemistry (medical) General Medicine In vitro Rats Kinetics Endocrinology medicine.anatomical_structure Strontium Biophysics Sodium-Potassium-Exchanging ATPase |
| Zdroj: | Biological trace element research. 34(1) |
| ISSN: | 0163-4984 |
| Popis: | ATP-dependent Sr2+ transport was examined in vitro using basolateral membrane (BLM) vesicles isolated from rat renal cortex to clarify the discrimination mechanisms between strontium (Sr) and calcium (Ca) in renal tubules during reabsorption. ATP-dependent Sr2+ uptake and Ca2+ uptake were observed in renal BLM vesicles and were inhibited by vanadate. Hill plots indicate similar kinetic behavior for Ca2+ and Sr2+ uptake. The apparentK m andV max of ATP-dependent Sr2+ uptake were both higher than those for Ca2+ uptake. ATP-dependent Sr2+ uptake by BLM vesicles diminished in the presence of 0.1 μM Ca2+ and was more markedly inhibited by 1 μM Ca2+. Hill plots of Sr2+ uptake data with and without 0.1 μM Ca2+ showed that the cooperative behavior of Sr2+ uptake was not changed by Ca2+. In the presence of 0.1 μM Ca2+, the affinity of the transport system for Sr2+ and the velocity of Sr2+ uptake in the BLM were both decreased. However, the rate of Ca2+ uptake was not diminished by Sr2+ concentrations of |
| Databáze: | OpenAIRE |
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